We spoke to the authors of a new book that aims to provide the kind of practical sex advice you'd never find in 'Cosmo'.

Over-consumption of crap sex advice has a tendency to make you feel like a well-trained circus animal, flipping nervously from position to position in the hope of a reward, mind skimming through your repertoire of tricks, eyes on your audience. Am I impressive? Am I doing this right? Will I get a round of applause?

But it doesn't have to be like this, says academic and psychotherapist Meg-John Barker and sex educator Justin Hancock, authors of Enjoy Sex: (How, when and if you want to): A Practical and Inclusive Guide, a new book that promises to contain not a single sex position.

VICE: Your book slates mainstream sex advice, suggesting that, by taking such a normative view, it actually creates the problems it claims to fix. Without naming anyone, can you give an example of terrible sex advice?Meg John: What I noticed – after going through 62 sex advice books – is that the mainstream ones all assume that penis-in-vagina (PIV) sex is what sex is, so most books are about different positions for PIV. But the way people's sexuality works, I don't think a list of positions covers it. Justin: And because we have such a narrow view of what "sex" means, almost half the population reports having a sexual difficulty, and 10 percent are distressed about their sex lives. That's because we have this very narrow idea which excludes anyone who isn't able to have what's seen as "normal" sex.

I was disappointed to hear there's no such thing as the perfect BJ technique. But you say the idea that there are failsafe activities which everyone enjoys is dangerous as it means we're less likely to ask for consent. An example of that would be the "surprise your partner" trope for spicing up your sex life. A bad idea, you reckon?MJ: Oh god, I read a whole "surprise your partner" book. It was divided into "for him" and "for her". It suggested that as soon as your partner gets home you push them into a chair and tie them up, or drop to your knees and get their cock out. I mean, how easy is it for that to stray into non-consent? Like really easy!J: It also perpetuates the idea that men like one thing and women like another. It's very 50 Shades – pretty much assuming that men are active and women are passive. There are so many myths in sex advice books: that women want love and men want sex. And actually, what a lot of this advice is saying is that women need to perform great sex or they'll lose their man.

Older people, or trans people, or people with disabilities are often talked about as special cases and given their own chapter, or own book, when it comes to sexuality. You make the point that everybody is different, physically, psychologically and socially. MJ: What's really brought this up for me recently is all these trans documentaries that are saying "here's this tiny group of people who are trans; should we be letting them have all these special things they need?" And I'm like, to the documentary-makers, just make a programme about gender. Loads of cis people have surgeries – like labiaplasty, breast augmentation, breast reduction, facial surgery. Loads of cis people take hormones – hormone replacement therapy, the pill. If you want to make a documentary about people who make various decisions about how they express their gender, follow a diverse range. And it's same with the book, really. Rather than taking a normative body and representing it in a million different positions, and assuming it works in these particular ways, let's talk about the diversity of bodies. Even if you took a cis man and a cis woman who are young and white and don't have any disabilities, you'd still find a huge diversity in terms of how their bodies work and what they enjoy sexually.

Your book has a really nuanced discussion of consent, and you talk about how being horny may only account for part of reason we have sex. People have sex for all kinds of reasons. MJ: I like the idea that we're learning from people on the edges. If you think about kinksters, you might have a scene that's about one person dominating another and there's no PIV, maybe no genital touching, and you think, 'What are those two people getting out of it?' Well, they're getting a really different thing. They're getting the experience of submission, the feeling of being out of control and able to let go; and the other person is getting the experience of feeling powerful and calling the shots and being able to read their partner. Those are legitimate things to want to get out of sex. Acknowledging that we have sex for different reasons can take the pressure off the idea that everyone should orgasm. To use a more normative example, you might just be up for being next to your partner when they orgasm because that would make you feel really close to them.

The idea that people with a penis will always want to penetrate and people with vaginas will always want to be penetrated just isn't accurate. How could we start talking about this in schools?J: I'm working on a project called dosreforschools.com, which MJ was an adviser on. We worked on the assumption that sex isn't just PIV. We're saying, "Here's how to find out what you enjoy and here's how to communicate that; here's how to make that safer; here's how you can practice self-care; here's how to negotiate that in relationships; and here's how to deal with all the messages we get from society." So we've kind of done a version of Enjoy Sex for schools.MJ: You can teach consent from a very young age. It doesn't need to be taught specifically in relation to sex. The whole point is that everything should be consensual, not just sex.

So go on then, what's your top sex tip?J: Learn to be present to everything that's happening, rather than going into it with some kind of end goal. If we constantly think that sex is like this ride we can't get off, that one thing inevitably leads to another, and that the goal is always PIV, then quite frankly we can be on the ride having rubbish sex and not even enjoying it. And being present – paying attention to what's going on with you and your partner – stands close to consent. We want to present the idea that "consent" and "enjoyable" are the same things.MJ: I'm aware these tips don't sound very sexy, but I think that self-consent and being present to yourself is extremely sexy. What it's about is really letting yourself find sexy what you find sexy, asking yourself, 'What is it that really excites me?' rather than pretending it's this thing that you think is "proper" sex or "normal" sex.